Generally, a massage bathtub is provided by injecting air or water from the water stored thereinto to collide the injected air or water against a bather's body, thereby massaging his or her body and releasing his or her muscle pain or fatigue.
The massage bathtub is largely classified into wet type bathtubs adapted to circulate and inject the water stored thereinto through a plurality of injection nozzles formed on the side surfaces of the bathtub by the activation of a pump, and dry type bathtubs adapted to inject the compressed air generated from an air blower through a plurality of injection nozzles formed on the bottom portion of the bathtub.
However, the wet type bathtubs need an independent pipe for circulating the water stored thereinto, thereby making it hard to install and repair the bathtub, and further, a relatively high installation cost is required. Thus, since the dry type bathtubs inject fine air bubbles into the water stored therein, without having any pipe for circulating the water, they have been recently popularized.
On the other hand, an example of the dry type bathtubs is disclosed in Korean Utility Model Registration No. 0349584 (entitled ‘air injection bathtub’).
According to the above-mentioned prior art, the air injection bathtub that is open on the upper portion thereof, the bathtub including: a body part having a plurality of air injection holes punched on the bottom surface thereof; a cover part disposed sealingly on the underside surface of the body part so as to cover the plurality of air injection holes; an air blower disposed inside a case placed at one side of the outside of the body part to convey air to the interior of the cover part; a heater disposed at the outlet of the air blower inside the case to heat the air; a hose connected between the outlet side of the case and one side of the cover part to convey the air passing through the heater; a check valve disposed at the center of the hose to shut off the reverse flow of the water in the hose; a remote controller adapted to control the air blower and the heater; and a valve disposed on the other side of the cover part to discharge the water remaining in the cover part.
According to the prior art, however, if the air injection into the air injection holes stops, the water stored in the bathtub is introduced into the space between the air injection holes and the cover part, and in this state, even though the air is injected through the activation of the air blower, the water is rarely discharged to the outside and still remains thereinto. Accordingly, the water is changed into foreign matters like water scale, and the foreign matters are discharged again to the interior of the bathtub through the air injection holes, thereby making the water in the bathtub dirty or causing bad odors from the water.